/*
* @(#)XletSecurity.java 1.6 06/10/10
*
* Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package com.sun.xlet;
import java.io.File;
import java.io.FilePermission;
import java.io.IOException;
import java.io.FileDescriptor;
import java.net.URL;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.net.SocketPermission;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.HashSet;
import java.util.StringTokenizer;
import java.security.*;
import sun.awt.AWTSecurityManager;
import sun.awt.AppContext;
import sun.security.provider.*;
import sun.security.util.SecurityConstants;
/**
* This class defines an xlet security policy
*
* @version 1.109, 01/23/03
*/
public
class XletSecurity extends AWTSecurityManager {
private AppContext mainAppContext;
/**
* Construct and initialize.
*/
public XletSecurity() {
this(AppContext.getAppContext());
}
public XletSecurity(AppContext appContext) {
// reset(); see reset().
mainAppContext = appContext;
}
// Cache to store known restricted packages
private HashSet restrictedPackages = new HashSet();
/**
* Reset from Properties
*
* this method exists to set additional package
* access restrictions, which in Applet's case provided
* in $USER/.appletviewer or $USER/.hotjava/properties file
* as "package.restrict.access.<pkgname>, * <true | false>".
* Xlets don't have this default property file, but I'm
* leaving the method for now and commenting out the call
* from the constructor.
*/
public void reset()
{
// Clear cache
restrictedPackages.clear();
AccessController.doPrivileged(new PrivilegedAction() {
public Object run()
{
// Enumerate system properties
Enumeration e = System.getProperties().propertyNames();
while (e.hasMoreElements())
{
String name = (String) e.nextElement();
if (name != null && name.startsWith("package.restrict.access."))
{
String value = System.getProperty(name);
if (value != null && value.equalsIgnoreCase("true"))
{
String pkg = name.substring(24);
// Cache restricted packages
restrictedPackages.add(pkg);
}
}
}
return null;
}
});
}
/**
* get the current (first) instance of an XletClassLoader on the stack.
*/
private XletClassLoader currentXletClassLoader()
{
/**
// try currentClassLoader first
ClassLoader loader = currentClassLoader();
if ((loader == null) || (loader instanceof XletClassLoader))
return (XletClassLoader)loader;
**/
ClassLoader loader;
// if that fails, get all the classes on the stack and check them.
Class[] context = getClassContext();
for (int i = 0; i < context.length; i++) {
loader = context[i].getClassLoader();
if (loader instanceof XletClassLoader)
return (XletClassLoader)loader;
}
// if that fails, try the context class loader
loader = Thread.currentThread().getContextClassLoader();
if (loader instanceof XletClassLoader)
return (XletClassLoader)loader;
// no XletClassLoaders on the stack
return (XletClassLoader)null;
}
/**
* Returns true if this threadgroup is in the xlet's own thread
* group. This will return false if there is no current class
* loader.
*/
protected boolean inThreadGroup(ThreadGroup g) {
if ( currentXletClassLoader() != null)
return getThreadGroup().parentOf(g);
return false;
}
/**
* Returns true of the threadgroup of thread is in the xlet's
* own threadgroup.
*/
protected boolean inThreadGroup(Thread thread) {
return inThreadGroup(thread.getThreadGroup());
}
/**
* Xlets are not allowed to manipulate threads outside
* xlet thread groups.
*/
public synchronized void checkAccess(Thread t) {
if (!inThreadGroup(t)) {
checkPermission(SecurityConstants.MODIFY_THREAD_PERMISSION);
}
}
private boolean inThreadGroupCheck = false;
/**
* Xlets are not allowed to manipulate thread groups outside
* xlet thread groups.
*/
public synchronized void checkAccess(ThreadGroup g) {
if (inThreadGroupCheck) {
// if we are in a recursive check, it is because
// inThreadGroup is calling xletLoader.getThreadGroup
// in that case, only do the super check, as xletLoader
// has a begin/endPrivileged
checkPermission(SecurityConstants.MODIFY_THREADGROUP_PERMISSION);
} else {
try {
inThreadGroupCheck = true;
if (!inThreadGroup(g)) {
checkPermission(SecurityConstants.MODIFY_THREADGROUP_PERMISSION);
}
} finally {
inThreadGroupCheck = false;
}
}
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to access the package specified by
* the argument.
* <p>
* This method is used by the <code>loadClass</code> method of class
* loaders.
* <p>
* The <code>checkPackageAccess</code> method for class
* <code>SecurityManager</code> calls
* <code>checkPermission</code> with the
* <code>RuntimePermission("accessClassInPackage."+pkg)</code>
* permission.
*
* @param pkg the package name.
* @exception SecurityException if the caller does not have
* permission to access the specified package.
* @see java.lang.ClassLoader#loadClass(java.lang.String, boolean)
*/
public void checkPackageAccess(final String pkgname) {
// first see if the VM-wide policy allows access to this package
super.checkPackageAccess(pkgname);
// now check the list of restricted packages
for (Iterator iter = restrictedPackages.iterator(); iter.hasNext();)
{
String pkg = (String) iter.next();
// Prevent matching "sun" and "sunir" even if they
// starts with similar beginning characters
//
if (pkgname.equals(pkg) || pkgname.startsWith(pkg + "."))
{
checkPermission(new java.lang.RuntimePermission
("accessClassInPackage." + pkgname));
}
}
}
/**
* Tests if a client can get access to the AWT event queue.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>AWTPermission("accessEventQueue")</code> permission.
*
* @since JDK1.1
* @exception SecurityException if the caller does not have
* permission to accesss the AWT event queue.
*/
public void checkAwtEventQueueAccess() {
AppContext appContext = AppContext.getAppContext();
XletClassLoader xletClassLoader = currentXletClassLoader();
if ((appContext == mainAppContext) && (xletClassLoader != null)) {
// If we're about to allow access to the main EventQueue,
// and anything untrusted is on the class context stack,
// disallow access.
super.checkAwtEventQueueAccess();
}
} // checkAwtEventQueueAccess()
/**
* Returns the thread group of the xlet. We consult the classloader
* if there is one.
*/
public ThreadGroup getThreadGroup() {
/* If any xlet code is on the execution stack, we return
that xlet's ThreadGroup. Otherwise, we use the default
behavior. */
XletClassLoader xletLoader = currentXletClassLoader();
ThreadGroup loaderGroup = (xletLoader == null) ? null
: xletLoader.getThreadGroup();
if (loaderGroup != null) {
return loaderGroup;
} else {
return super.getThreadGroup();
}
} // getThreadGroup()
/**
* Get the AppContext corresponding to the current context.
* The default implementation returns null, but this method
* may be overridden by various SecurityManagers
* (e.g. XletSecurity) to index AppContext objects by the
* calling context.
*
* @return the AppContext corresponding to the current context.
* @see sun.awt.AppContext
* @see java.lang.SecurityManager
* @since JDK1.2.1
*/
public AppContext getAppContext() {
XletClassLoader xletLoader = currentXletClassLoader();
return (xletLoader == null) ? null : xletLoader.getAppContext();
}
} // class XletSecurity